Intake manifold



5f i532 R. P. SMITH INTAKE MANIFOLD Filed July 1e, 1930 2 SheetsheetA 1 Gttorneg fb@ @QQ Sept. 6, 1932. R p. $M|VTH 1,875,670

'INTAKE MANIFOLD Filed July 16, 1930 2 Sheets-Sheet 2 Fig.

R.P.Smith nventor Patented Sept; V6, 1932 my und! sm'rmvor rmroxim i v morn Application ma my 1e. 1930. serial no. mass,

The present invention relates to in ternal combustion engines, and has more particular reference to an improved manifold construction.

An object of the present invention is to provide an -improved manifold of th1s type by means of which the mixture from the carburetor may be properly and equally distributed to the various intake openings of the engine block, and so that the suction in the manifold will be uniform throughout its entire length and branches, and so that the remote cylinders at opposite ends of the block will be supplied with the relatively adequateJ amount of the charge.

A further object of this invention is to provide an intake manifold for internal combustion engines by means of which economy in consumption of fuel will be effected, which will better the operation of the engine, which will increase the speed and horse power of the engine relative to the amount of fuel consumed and which will provide easierv starting of the engine during all seasons of the year.

The invention also aims at the provision of an intake manifold embodying the above pointed out characteristics, and which is of such construction that it may be readily substituted for manifolds at present in use without requiring change in equipment or modiications in the construction of either the carburetor or the engine block.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claim appended hereto. y j

In the drawings, whereinlike symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a top plan view of a centralv block having a manifold constructed accord-y ing to the present invention applied thereto and Figure 2 is a side elevation of the same, parts being shown in section.

Referring to the drawings 10 designates a:

`bolts 22 or the like.

of disclosure yis shown in the pes'entinstance for a six cylinder internal c ombustion'engine. The intake passages 1'1 areshown in dotted lines at one .side of theblock and are three in number ,each passage '11 leading ,to 55 two adjacent cylinders and opening to the intakev ports orvalves'thereof and'thevpassages 11 opening; atythree, spaced points "alongside of theblock 10 in the usual .mang ner. l

\ The manifold of the present.` invention comprises a horizontal or straight line vsection 12 of substantially: pipe form, and which is provided'at each end and at an intermediate point with a couplingvnipple 13 terminat- QI ing `in an 'attaching flange V14'r adapted to be vsecured b bolts 15 or the like tp the side'of the cylin er block 10 in registry' withthe respective intake passages 11. The horizontah` section 12 is provided intermediateits Sends'lo with a vertically disposed branch 16 vcornmunicatingwith-the horizontal secti0n12 and .of substantially thesamediameter asthe same `and opening into ythe branch adjacent to the intermediate nipple 13. The horizontal sec- 76 tion 12 is also provided at opposite'ends with intercommunicating upwardlyk converging or v y inclined 4branches 17 of the same diameter as the horizontal branch 12, and which open into* the ends of the branch 12 adjacent to theend 80 f nipples 13. The branches y1'( converge up-4 wardly and merge at their upperends into the upper end of the vertical section 16` and ,intercommunication therewith. The three branches 16 and 17 open into an elbow cou 85 pling section 18, which is overturned and provided at its free downwardly opening end with an attaching flange 19 tof which the. flange20 of a carburetor 21 is securedby o The manifold thus constructed is of the top feed type wherein the mixture from the carburetor 21 is carried upwardly and over through the elbow 18 .into the top of the manifold and fromfthe elboxv` A18 is drawn by, 9

equal pressuredown-wardly through` the diverging end branches'l? ,and the vertical central branch 16 intothe-lower horizontal section 12 at the inner endsof the` respective nipples 13. Should there be an unequal pressure at the intake nipples 13 the cross, horizontal or intercommunicating branch 12 establishes a suitable connection-between the nipple for equalizing the pressure at the same and insuring the proper and even supply of the mixture to all three of the nipples 13.

While the manifold has been disclosed in the present instance in connection with a six cylinder engine, it is'to be. understood .that the lconstruction maybe so modified and ar-v v ranged as to adapt the manifold to` engines of a greater or lesser number of cylinders.

It is important that there be a direct lead from the carburetor connection to the indi- Vidual supply nipples 13, and that there also be a cross connection between the nipples so as to vequalize the pressure throughoutthe manifold and insure theproper and even distribution of the fuel charge;

lIt willbe noted thata down draft intake manifold is provided wherein the diverging branches 17'` communicate with the outer ends' Hof the main body or cross portion 12 and also intercommunicate" with the' upper en'd of the vertical branch 16 ata point near thevelbow Referring now to Figure 1 it will be noted that the gaseous mixture is drawn directly down to the forward lcylinders V1 and 3 through the forward branch 17 and tothe rear cylinders 5 and6 through the rear branch 17 the intermediate or central cylinders 2 and 4 being supplied with the mixture through tlhe vertical branch 16 directly from thel elbow Asis at present the kcase without lthejuse of the upwardly convergingend branches 17,

the forward and rear cylinders receive less of the gaseous mixture than is received' bythe central cylinders'.-k Further, rthe central cylinders 2 'and- 4 receive a richer and more thoroughly carburetted mixtureV than the outer l creased.

cylinders with the result that the smooth run ofthe motor cannot be had andfconsequentl;T the vibration of the Amotor is in y It will also be notedth atlwith the construe tion disclosed bythe present invention .when

' the motor is not running the mixture will he permitted to remain in the conduits 12 and 17 for a considerable length of time and that,

therefore, the-engine may be easily started incident to this accumulation of the charge in the manifold beyond the carburetor and immediately adjacent to the intake passages. 11.

I do not wish to be restricted to the size,

i form, and proportions. of the various parts, v and obviously changes could be made in the constructionherein described vwithout desi gnature.

' RAY PERCY SMITH.

parting from'the spirit of the invention, it e bein only necessary that such changes fall withmfthe scopeof the appended claim. I

What is clalmed is v f'f A down`v draft intake manifold for internal combustion engines, comprising a horizontal 

